1. Field of the Invention
The present invention relates to an image forming device that prints out a data file, and particularly relates to an image forming device that prints out a data file including a data body, which is printed out, and additional data, which is not printed out.
2. Description of the Related Art
A data file including a data body such as document data and image data is generally managed by a computer system. The data file includes authentication data as additional data, and an original copy of the data file is assured.
The authentication data may include, for example, an electronic signature and a timestamp. A hash value of the data body of the data file and the timestamp are encoded and stored in the electronic signature. The hash value of the data body and the date and time when the authentication data was generated are encoded and stored in the timestamp.
A hash value can be generated from the data body of the data file, and the hash value of the data body stored in an electronic signature can be decoded. When the hash values match, it can be confirmed that the data body has not been falsified. By a similar process, it can be confirmed that the electronic signature corresponds with the timestamp, and date and time when the authentication data has been assigned to the data file can be confirmed by the timestamp.
Although a computer device manages such a data file, the computer device may transmit the data file to a printer device, and the data file may be printed out onto a printing medium. In such a system, for example, the computer device converts the data file into print data, and the print data is transmitted to the printer device. Therefore, the printer device prints out the received print data.
In such a case, although the data body of the data file is of course printed out, the authentication data used for an authentication process is not printed out.
Further, the data file with the authentication data is generally important. According to one conventional art, when a data file with authentication data is transmitted from a computer device to a printer device, the printer device executes an authentication process on the data file by the authentication data. Then, the printer device prints out an authentication result as an authentication mark or the like along with the data file.
According to another conventional art, authentication data as described above is printed out as machine-readable print data along with data body of a data file. In this case, a scanner device scans a print result, and the authentication data is decoded to execute an authentication process.
According to another conventional art, identification data of an operator is entered into such a scanner device, and an authentication process is executed on the identification data by authentication data decoded from a scanned image. When a determination is made that the operator is inappropriate, warning data is added to a scan result, and the scan result is output.
In the above-described device, the authentication process is executed on the identification data of the operator by the authentication data scanned from a printed-out image. When the operator is determined to be inappropriate, warning data is added to the scan result, and the scan result is printed out.
An operator, who scans a printed-out image by the scanner device, is authenticated by the authentication data decoded from the printed-out image. However, an operator, who prints out a data file stored in the computer device by the printer device, cannot be authenticated by the authentication data of the printed-out data file.
In the above-described device, the authentication result is printed out along with the data file. Therefore, the authentication result may be confirmed along with the printed-out image of the data file. However, the authentication data includes various data such as the electronic signature and the timestamp as described above. Therefore, in order to print out a detailed authentication result, when the authentication data or the like is included in the authentication data, a volume of the authentication result increases.
However, when printing out the authentication result along with the data file as described above, since an original object is to print out the data file, it is difficult to secure a sufficient print region for the authentication result. Therefore, a simple authentication mark or the like has been conventionally printed out to enable just success or failure to be distinguished in the authentication result. However, a detailed authentication result cannot be confirmed with such a simple authentication mark. In addition, data of the detailed authentication result cannot be managed based on the print result.